In existing combustion systems including a boiler, thermal energy is generated as a result of combustion of fuel such as coal in the boiler, and then, for example, the thermal energy is converted into electric energy. The combustion of fuel in the boiler generates an exhaust gas containing nitrogen oxide.
The exhaust gas generated in the boiler is discharged to the outside from the b through an exhaust line. In consideration of environmental factors, nitrogen oxide is removed, by a denitration device, from the exhaust gas that is discharged to the outside from the boiler.
In general, a denitration catalyst such as a vanadium/titanium catalyst (V2O5/TiO2) is used for denitration devices that remove nitrogen oxide from exhaust gas. The vanadium/titanium catalyst exhibits high catalytic activity in a high-temperature (e.g., about 370° C.) environment. Therefore, such a denitration device is disposed in an area near the outlet of exhaust gas in a boiler or on the upstream side of an exhaust line in, for example, a thermal power plant (e.g., refer to Patent Document 1).
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2011-190940